Synthesis of Eu3+-activated BiOF and BiOBr phosphors: photoluminescence, Judd-Ofelt analysis and photocatalytic propertiesElectronic supplementary information (ESI) available. See DOI: 10.1039/c4ra16645k

A series of Bi 1− x Eu x OX (X = F and Br; x = 0, 0.01, 0.03 and 0.05) phosphors were synthesized at relatively low temperature and short duration (500 °C, 1 h). Rietveld refinement results verified that all the compounds were crystallized in the tetragonal structure with space group P 4/ nmm (no. 129). Photoluminescence spectra exhibit characteristic luminescence 5 D 0 → 7 F J ( J = 0-4) intra-4f shell Eu 3+ ion transitions. The magnetic dipole ( 5 D 0 → 7 F 1 ) transition dominates the emission of BiOF:Eu 3+ , while the electric dipole ( 5 D 0 → 7 F 2 ) peak was stronger in BiOBr:Eu 3+ phosphors. The evaluated CIE color coordinates for Bi 0.95 Eu 0.05 OBr (0.632, 0.358) are close to the commercial Y 2 O 3 :Eu 3+ (0.645, 0.347) and Y 2 O 2 S:Eu 3+ (0.647, 0.343) red phosphors. Intensity parameters ( Ω 2 , Ω 4 ) and various radiative properties such as transition rates ( A ), branching ratios ( β ), stimulated emission cross-section ( σ e ), gain bandwidth ( σ e × Δ λ eff ) and optical gain ( σ e × τ ) were calculated using the Judd-Ofelt theory. It was observed that BiOBr:Eu 3+ phosphors have a long lifetime ( τ ) and better optical gain ( σ e × τ ) as compared to reported Eu 3+ doped materials. Furthermore, these compounds exhibit excellent photocatalytic activity for the degradation of rhodamine B dye under visible light irradiation. The determined radiative properties and photocatalytic results revealed that BiOBr:Eu 3+ phosphors have potential applications in energy and environmental remedies, such as to develop red phosphors for white light-emitting diodes, red lasers and to remove toxic organic industrial effluents. A series of Bi 1− x Eu x OX (X = F and Br; x = 0, 0.01, 0.03 and 0.05) phosphors were synthesized at relatively low temperature and short duration (500 °C, 1 h).